1. Field of the Invention
The present invention relates to imaging apparatuses and methods, and in particular, to an imaging apparatus using an imaging device that converts light from a subject into electric signals and a method of imaging thereof.
2. Description of the Related Art
As an imaging apparatus, a pinhole camera is well-known. In the pinhole camera, light reflected from a subject is guided onto a photosensitive material, such as a film, in a dark box through a hole, called a pinhole, formed on one surface of the dark box, thus imaging the subject. In the pinhole camera, slight light passing through the pinhole reaches one point on the photosensitive material. Therefore, the amount of light is small. In imaging under low light conditions, particularly, in dark places, the pinhole camera is of little practical use.
A generally known imaging apparatus is disclosed by Takemura Hiroo, “CCD Kamera Gijutse Nyumon [Introduction to CCD Camera Technology]”, first edition, Corona Publishing Co., Ltd., August 1998, pp. 2-4. The imaging apparatus includes an imaging lens 101 as shown in FIG. 24. The apparatus has a structure in which an imaging device 102 is arranged in the focal position of the imaging lens 101, light from a subject captured by the imaging lens 101 is subjected to optical processing through an optical system 103 so that the imaging device 102 easily converts the light into electric signals, the resultant light is guided onto a photoelectric conversion portion of the imaging device 102 so that the light is converted into electric signals, and electric signals obtained through the imaging device 102 are subjected to predetermined signal processing by a signal processing circuit 104 arranged downstream of the imaging device 102.
This type of imaging apparatus is used solely as a camera system, e.g., a digital still camera. Furthermore, the imaging apparatus can be incorporated into a compact portable device, such as a mobile phone. Actually, reducing the size, weight, and cost of the imaging apparatus is strongly desired in incorporating the apparatus into a mobile phone. In other words, the use of a small-sized, lightweight, and low-cost imaging apparatus extremely contributes to the reduced size, weight, and cost of a compact portable device, such as a mobile phone.